Understanding the role of the microbiota components in either preventing or favoring enteric infections is critical. Here, we report the discovery of a Listeria bacteriocin, Lmo2776, which limits Listeria intestinal colonization. Oral infection of conventional mice with a Δlmo2776 mutant leads to a thinner intestinal mucus layer and higher Listeria loads both in the intestinal content and deeper tissues compared to WT Listeria. This latter difference is microbiota dependent, as it is not observed in germ-free mice. Strikingly, it is phenocopied by pre-colonization of germ-free mice before Listeria infection with Prevotella copri, an abundant gut-commensal bacteria, but not with the other commensals tested. We further show that Lmo2776 targets P. copri and reduces its abundance. Together, these data unveil a role for P.copri in exacerbating intestinal infection, highlighting that pathogens such as Listeria may selectively deplete microbiota bacterial species to avoid excessive inflammation.

了解微生物群成分在预防或促进肠道感染中的作用至关重要。在这里，我们报告了李斯特菌细菌素Lmo2776的发现，它限制了李斯特菌的肠道定殖。与WT李斯特菌相比，常规小鼠经口Δlmo2776突变体的口腔感染会导致肠粘液层更薄，肠内含量和组织更深的李斯特菌负荷更高。后一种差异是微生物群依赖性的，因为在无菌小鼠中未观察到。令人惊讶的是，在利斯特氏菌感染普氏杆菌之前，通过无菌细菌小鼠的预先定殖来对它进行表型复制。，一种丰富的肠道共生细菌，但未与其他经过测试的共生细菌一起使用。我们进一步表明，Lmo2776靶向粉虱（P. copri）并降低了其丰度。这些数据共同揭示了P.copri在加剧肠道感染中的作用，强调了诸如李斯特菌的病原体可以选择性地消耗微生物菌群以避免过度的炎症。